15 Fascinating Octopus Facts You Need to Know

Octopus facts… What if I told you they can be your friends and love you? Yes, you heard that right. But of course, this can only happen if you’re a diver.

In fact, it has happened before. There’s an incredible story about an unusual friendship that bloomed between a female octopus and a South African diver, Craig Foster. Throughout their friendship, Craig learned interesting octopus facts about the life of these animals: how they change their shape and color to blend in and protect themselves, their extraordinary intelligence, their capacity for learning, and their ability to devise hunting strategies.

But beyond the octopus’ skills, what really impressed Craig was its personality: the octopus had self-awareness, an excellent memory, and a playful spirit that made it stand out as a fascinating being. The relationship between the octopus and Craig was so intense and moving that it became the central theme of the documentary “My Octopus Teacher,” which recently won an Oscar in Hollywood.

The friendship lasted as long as an octopus’ life, and if you read this article, you’ll find out how long that is. Get ready for an unforgettable adventure!

Facts: Octopus Basics

 1. What is an octopus

Octopuses are cephalopods, a class of marine invertebrate animals belonging to the phylum Mollusca. What characterizes them all is that they have appendages or legs coming out of their heads. Among them, we find cuttlefish, squid, and our friends the octopuses.

On their own, octopuses have their own animal order: Octopoda. A word that comes from the Greek “oktṓ” meaning ‘eight’ and ‒́podo meaning ‘foot’.

Up to 300 species of octopuses have been recorded in the world. In today’s article, we will get to know the 6 species that are most commonly found when diving in the Caribbean.

2. Octopi Or Octopuses

We need to agree on this point before continuing. The word “octopus” in English causes controversy when it comes to its plural form. When referring to a single octopus, there is no issue. However, we are talking about the plural form of octopus. Which is correct: octopuses, octopi, or octopodes? This confusion stems from the nuances of language.

Firstly, we have “octopi”. This plural form is the oldest and comes from the idea that Latin-derived words should have Latin endings. However, it’s important to note that this is actually a misconception because the word is of Greek origin.

On the other hand, we have “octopodes”. This plural form is correct as it incorporates a Greek ending to indicate the plural. So, if you want to impress your friends with your linguistic knowledge, you can use this etymologically correct plural form.

Last, but not least, we have “octopuses”. This plural form uses the English ending “es” like any other English word. For grammar enthusiasts, this is the correct plural form. We will use this form in this article.

There is no doubt that the quirks of language provide us with interesting facts about the octopus.

Octopus Anatomy Facts

3. How Big Are Octopus

In general, the size of an octopus will depend on its species. There are as many sizes of octopuses as there are species. For example, the smallest species is the Octopus wolfi, which measures around 2.5 cm and weighs less than 1 g. It’s so tiny you could have it perched on your finger!

On the other hand, there are also giant species, such as the Pacific giant octopus, which not only holds the record for being the largest species but is also the longest-living octopus species known. Did you know that on average, a Pacific giant octopus measures around 5 meters and weighs 50 kilograms? Impressive! In fact, the largest Pacific giant octopus ever found measured 9 meters across and weighed 272 kilograms.

4. Octopus body parts

We can distinguish three basic parts in the body of an octopus.

Head: This is where octopuses store their main brain and their hearts. “What do you mean, they have more than one brain? And why do they need three hearts?” you might be wondering. Don’t worry, I’ll explain in just a moment.

Mantle: This is the area that connects the limbs to the head and where the animal’s viscera are located. This is also where the octopus’s beak, which it uses to feed, its siphon, which it uses to expel water and move, and its urinary bladder are located.

Limbs: The octopus’s eight tentacles are muscular and strong. They have suction cups on their inner side and millions of nerve endings that allow the octopus to move each tentacle individually. Amazing! Isn’t it?

5. Octopus Hearts

They have three hearts and their blood is blue. Now that’s an interesting fact about octopuses!

The truth is that octopuses have a closed circulatory system consisting of a dense network of capillaries. To provide this circulatory system, they have a systemic heart.

The systemic heart takes oxygenated blood from the gills and circulates it throughout the rest of the body.

The two branchial hearts function to increase the pressure of circulation so that deoxygenated blood returns to the gills as quickly as possible.

And they also have blue blood.

Yes, I’ve already mentioned it, but everything is related.

The oxygen consumption of octopuses is enormous, but instead of hemoglobin, their blood contains hemocyanin. Both substances are proteins that serve to carry oxygen to the blood. However, the hemocyanin in octopuses’ blood does not contain iron, but rather copper, whose oxidized state gives it its blue color. Nonetheless, copper is not as efficient at transporting oxygen, so they need two extra hearts.

6. Octopus Head

It is common to see posts claiming that octopuses have nine brains. This is false.

What they actually have is a central brain and 8 ganglia, one for each arm. We could say it is a brain with delegations, like in a company. The central brain is one, but its bases are part of it, providing service to the different arms. The same goes for the octopus and its complex nervous system.

The octopus’ central brain is the largest among invertebrates and is protected within a cartilage capsule. However, this brain is only a small part of its neural network. This network extends throughout the body supported by a constellation of neurons (100,000,000-500,000,000), allowing them to make rapid adaptations. For example, each of their arms can move independently of the others or coordinately, if necessary, because everything is interconnected.

Furthermore, the octopus possesses enormous intelligence: it can use tools, solve problems, and learn. Additionally, they feel complex emotions like humans, chimpanzees, or dogs, and even form friendships.

7. Its Beak and More Octopus Fun Facts

Beak

Caribbean divers! Did you know that all cephalopods have a parrot-like beak? This beak is a structure consisting of a pair of strong, jaw-like mandibles surrounded by powerful muscles that function like scissors, with the upper jaw fitting over the lower jaw.

Suction cups

With eight tentacles around its mouth, each bearing two rows of suction cups, the octopus is a skilled hunter capable of capturing prey with ease. Interestingly, octopuses are able to process sensory and motor information through their arms, without requiring input from their central brain. The suction cups can even coordinate with each other and take action based on stimuli.

With around 240 suction cups on each arm, a common octopus is a true titan of strength, able to hold onto objects weighing up to 15 kilograms with a single suction cup. But even more amazing is the sensitivity of these creatures: they can detect subtle chemical signals and move with incredible agility, even bending their tentacles to make pinching motions.

Propulsion system

Surely, you’ve noticed the impressive ability of octopuses to move quickly and nimbly underwater. Did you know this is due to an ingenious propulsion system? The octopus sucks in water through its gills and directs it towards its siphon, which forcefully expels the water and propels the octopus at high speeds.

Eyes

Here’s another interesting fact about octopuses. Their eyes have a structure similar to that of mammals, which gives them exceptional vision both up close and at long distances.

Octopus Habitat and Diet

8. Octopus Habitat

Octopuses can be found in virtually all oceans of the world regardless of water temperature. Their preferred areas are coral reefs and rocky zones, where they take shelter among small crevices and under rocks.

While most species of octopuses live on the ocean floor, some young offspring live near the surface and move deeper as they grow. Additionally, octopuses can adapt to different areas and temperatures, which has allowed them to survive for millions of years.

9. What Do Octopus Eat

Their primary diet consists of mollusks and crustaceans, although they also eat fish and snails. Sometimes, they even feed on smaller octopuses. And if they ever come across a prey that’s difficult to eat, they release a toxin that dissolves the tissues connecting the food to its shell.

10. How Does an Octopus Eat

These intelligent creatures are skilled hunters, able to see in the dark and use murky waters to their advantage. They typically hunt at night, but can also catch prey during the day if they’re hungry enough.

Octopuses have a unique digestive process, with food passing through their brain before entering their temporary storage sac, the stomach. After that, special glands in the stomach trigger the digestion process. Keep your eyes peeled for these fascinating creatures on your next dive!

Life of An Octopus

11. Octopus Life Cycle

Males must create small sperm packets called spermatophores and transfer them to females via a modified arm that they use as a sexual organ.

Females can store the sperm of multiple males for months before using it for fertilization. The embryonic development lasts up to 4 months, and after hatching, thousands of small “paralarvae” emerge into the water with jaws and teeth to hunt.

They travel through the ocean thanks to the currents and can remain in the water column for upto 3 months before settling on the bottom as juveniles.

12. Common Octopus Lifespan

As the common octopus’s life cycle completes in a single reproductive event, its lifespan lasts only for a year or a year and a half.

After the female lays eggs, her attention is solely focused on their care. This emphasis on breeding leads to a decrease in food intake and ultimately death by starvation. This pattern of “programmed suicide” also seems to occur in males, who stop feeding once they reach their expected maximum age.

13. Octopus Predators

The octopus has several natural predators, some of which include sharks and other large fish such as tuna and swordfish. Some seabirds, such as seagulls and cormorants, hunt octopuses by diving into the water to catch them when they swim near the surface.

Whales, dolphins, and seals also eat octopuses, and of course, another predator is humans. The location and species of the octopus determine which predators it will have to face.

The octopus is most vulnerable when it is young, as it lives near the surface of the water and can be easily hunted by other animals. Incredibly, over two-thirds of young octopuses can be eaten in the first few weeks of life! That’s why, even though a female octopus can lay more than 200,000 eggs, most of them don’t survive to adulthood due to the number of predators they face.

Octopuses have to be very alert and take care to survive in their habitat.

14. Octopus Adaptations

Thank goodness for the expert defense tactics of octopuses! When they feel threatened, these creatures can bite hard and release paralyzing venom.

They have the ability to camouflage and hide in small spaces to evade predators.

If that doesn’t work, they can release ink to disorient their attackers. It’s like they carry their own defense kit!

Moreover, some octopuses have the astonishing ability to change color to blend in with their environment, and there is even a species, the mimic octopus, that can mimic the physical appearance and behavior of over fifteen different species.

Types of Octopus

15. Caribbean Octopus Species

In summary, among all these interesting facts about octopuses, there is one that is truly unsettling. We’ve talked about how octopuses are invertebrate marine animals, extremely intelligent, with three hearts and a plethora of evolutionary adaptations for survival, and yet they don’t live much longer than a year. We’ve also learned about the six most common species in the Caribbean.

If you found all these octopus facts interesting, just wait until you see them face to face. You’ll enjoy the encounters to the fullest! Now that you know so much more about octopuses, write us an email and come to the Caribbean to see them.